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N Sato

Publications and source records attributed to N Sato.

At least 91 records · Page 5Linked to original sources
PubMed2003

A possible target of antioxidative therapy for diabetic vascular complications-vascular NAD(P)H oxidase.

A growing body of evidence has shown that oxidative stress may be involved in the development of vascular complications associated with diabetes. However, the molecular mechanism for increased reactive oxygen species (ROS) production in diabetes remains uncertain. Among various possible mechanisms, attention have increasingly been paid to NAD(P)H oxidase as the most important source of ROS production in vascular cells. High glucose level stimulates ROS production through protein kinase C (PKC)-dependent activation of vascular NAD(P)H oxidase. Furthermore, the expression of NAD(P)H oxidase components is increased in micro- and macrovascular tissues of diabetic animals in association with various functional disorders and histochemical abnormalities. These results suggest that vascular NAD(P)H oxidase-driven ROS production may contribute to the onset or development of diabetic micro- or macrovascular complications. In this point of view, the possible new strategy of antioxidative therapy for diabetic vascular complications is discussed in this review.

Animals↗
PubMed2003

[Results of surgical treatment of pulmonary metastatic tumors and analysis of prognostic factors].

We evaluated surgical outcome and prognostic factors in 35 patients who underwent surgery for pulmonary metastatic tumors. Overall 5-year survival rate was 55.3%. Size of lesions and disease free interval were considered as affecting factors for survival, but not statistically significant. Because number of resected tumors, surgical procedure, laterality (unilateral or bilateral) did not significantly affect survival, we considered that partial resection was appropriate for pulmonary metastases if tumors were complete resected. Tumor size and preoperative serum carcinoembryonic antigen (CEA) levels were significant factors influencing survival for patients of colorectal carcinoma, Ki-67 positive cell ratio for patients of colorectal and breast carcinoma.

Adult↗
PubMed2003

[Acute massive pulmonary embolism occurring during orthopedic surgery].

We present an emergent surgical case of massive pulmonary embolism (MPE) that happened during orthopedic surgery. A 38-year-old man, who had bone fractures with his lumbar vertebra and ankle, underwent the internal fixation of the tibial bone with tourniquet under general anesthesia in our hospital. During this surgery, the pulse oxymeter showed a drop of arterial oxygen saturation suddenly. Immediately we installed a transesophageal echo (TEE) probe in the patient, and detected enlargement of the right ventricle and right atrial thrombus. Half an hour later, the thrombus disappeared from the right atrium and the patient showed hemodynamic shock. We performed emergent embolectomy immediately under moderate hypothermic complete cardiopulmonary bypass. The postoperative course was uneventful, and one month later, his orthopedic surgery underwent completely. We conclude that TEE was a useful devise for the diagnosis of intraoperative MPE.

Adult↗
PubMed2003

Differential gene expression screening between parental and highly metastatic pancreatic cancer variants using a DNA microarray.

To clarify the difference in genes expressed in hematogenous metastasis and peritoneal dissemination, a broad analysis of differential gene expression analysis between parental cell lines and established metastatic sublines was performed. Using an oligonucleotide array (Gene Chip, Affymetrix), approximately 2,000 genes involved in cancer were analyzed for each of the cell lines. HPC-4H4 (highly metastatic lines to the liver) compared with HPC-4 (low metastatic parental lines), in which 20 overexpressed genes and 5 underexpressed genes were recognized. HPC-4P4a (highly metastatic to the peritoneum) compared with HPC-4, in which 12 overexpressed genes and 15 underexpressed genes were also recognized. Analysis of HPC-4H4 and HPC-4P4a showed comparative up-regulation of 20 genes and down-regulation of 13 in the former, HPC-4H4. Further studies are needed to validate our hypothesis that some of the resulting differentially expressed genes might be implicated in the development of metastasis in pancreatic cancer. In conclusion, this genome-wide expression analysis will help to clarify the molecular mechanisms of cancer metastasis and of the different levels of gene expression in a variety of metastatic potentials in pancreatic cancer.

Cell Line, Tumor↗
PubMed2003

Metastatic-associated biological properties and differential gene expression profiles in established highly liver and peritoneal metastatic cell lines of human pancreatic cancer.

To elucidate metastasis mechanisms, we established a Panc-1H5 subline with a highly liver metastatic cell line and a Panc-1P4a with a highly peritoneal metastatic cell line, which were sequentially selected from the parental pancreatic cancer cell line Panc-1. Using these three cell lines, we investigated several biological properties and mRNA levels of differentially-expressed genes involved in cancer metastasis with a cDNA macroarray. The tumorigenicity, motile activity, adhesive activity and cytokine production of metastatic sublines were higher than those of parental Panc-1 cells. Particularly, in Panc-1H5 cells, adhesive activity to the extracellular matrix and angiogenetic factors increased, whereas in Panc-1P4a cells, motile activity was extremely enhanced compared with Panc-1 cells. Histopathological findings for the three cell lines were the same. In cDNA macroarray analysis of Panc-1H5 cells, 11 genes were up-regulated and 20 genes were down-regulated compared with parental Panc-1 cells. In Panc-1P4a cells, 7 genes were up-regulated and 13 genes were down-regulated compared with parental Panc-1 cells. This study provides a demonstration of global gene expression analysis of pancreatic cancer cells with liver and peritoneal metastasis and these results provide new insight into the study of human pancreatic cancer metastasis.

Animals↗
PubMed2002

Long anchor using Flo1 protein enhances reactivity of cell surface-displayed glucoamylase to polymer substrates.

We investigated the influence of anchor length on the reactivity to polymer substrate of enzyme displayed on yeast cell surfaces. Using various lengths [42, 102, 146, 318, 428, and 1,326 amino acids (aa)] of the C-terminal region of the Saccharomyces cerevisiae Flo1 protein (Flo1p), which plays a major role in yeast flocculation, six display systems with various anchor lengths were constructed. In these systems, the target protein was displayed on the yeast cell surface under the control of the 5'-upstream region of the isocitrate lyase gene of Candida tropicalis ( UPR-ICL). Cell-surface display of Rhizopus oryzae glucoamylase by these systems was induced and confirmed in all systems by immunofluorescence microscopy and immunoblotting. Flow-cytometer measurement of the fluorescence intensity of immunofluorescence-labeled yeast cells displaying glucoamylase indicated that glucoamylase displayed with longer anchors, especially those of 428 and 1,326 aa in length, had higher reactivity to antibodies. The reactivity of starch to displayed glucoamylase, which was evaluated by plate assay, increased with anchor length, as did the cell growth-rate in starch-containing medium. These results indicate that cell-surface display systems using 428- and 1,326-aa length anchors of Flo1p are effective for the display of enzymes on the outer surface of yeast cells.

Cloning, Molecular↗
PubMed2002

A case of true malignant histiocytosis: identification of histiocytic origin with use of immunohistochemical and immunocytogenetic methods.

We report here an autopsy case of true malignant histiocytosis. The patient was a 67-year-old woman who exhibited fever, wasting, hepatosplenomegaly, and progressive pancytopenia. The bone marrow aspiration disclosed hemophagocytosing cells, which resembled histiocytes. The molecular analysis did not show the clonal gene rearrangement of T-cell receptor or immunoglobulin heavy chain. Although the patient had been started on methylprednisolone pulse therapy and chemotherapy with etoposide, she died from cerebral hemorrhage. The autopsy specimens of spleen and liver showed extensive infiltration of atypical cells, for which histiocytic origin was identified with an immunohistochemical method using monoclonal antibodies against CD11c, CD68, macrophage colony-stimulating factor (M-CSF), M-CSF receptor, lysozyme, antitrypsin and alpha1-antichymotrypsin. Recent investigations have disclosed that in most cases diagnosed as malignant histiocytosis, hemophagocytosis was reactive and not evoked by histiocytic malignancy. True malignant histiocytosis, for which histiocytic origin is confirmed, is extremely rare.

Aged↗
PubMed2002

Collapse of valence transition in Yb0.8Y0.2InCu4: pressure-induced weak ferromagnetism.

We investigated the magnetization of Yb0.8Y0.2InCu4 as a function of temperature down to 0.6 K, pressure up to 1.2 GPa, and magnetic field up to 9 T. The valence transition temperature of Yb0.8Y0.2InCu4 is lowered with applying pressure. At 0.8 GPa, collapse of the valence transition and ferromagnetic ordering occur almost simultaneously. The ferromagnetic phase at 1.2 GPa is characterized by a low Curie temperature of 1.7 K and an extremely small ordered moment of 0.05 micro(B) per Yb. Some effect of screening the ordered moment may play a key role in the ferromagnetism and the valence transition.

Journal Article↗
PubMed2002

Haemodynamic and splanchnic organ blood flow responses during sevoflurane-induced hypotension in dogs.

BACKGROUND AND OBJECTIVE: The safety of hypotension induced by sevoflurane and splanchnic organ blood flow remains to be clarified. The aim was to investigate the effects of sevoflurane-induced hypotension on systemic haemodynamics and splanchnic organ blood flows in dogs. METHODS: Mean arterial pressure was maintained at 60 mmHg by increasing sevoflurane concentrations. The renal, hepatic and pancreatic blood flows were measured by using the hydrogen clearance method. RESULTS: Hypotension induced by sevoflurane resulted in a 50% decrease of mean arterial pressure due to a 30% reduction in systemic vascular resistance associated with a 30% decrease in cardiac index. The mechanisms causing the lower cardiac index were produced by the decreases in heart rate and left ventricular dP/dt(max). Renal, hepatic and pancreatic blood flow were reduced, but the whole-body oxygen consumption did not change during the hypotensive period. CONCLUSIONS: The haemodynamic changes induced by sevoflurane were caused by the suppression of arterial baroreflexes and myocardial depression, but splanchnic organ blood flows, though reduced, could provide adequate peripheral perfusion to meet the decrease in oxygen supply.

Anesthetics, Inhalation↗
PubMed2002

Comparison of T1c versus T2 prostate cancers in Japanese patients undergoing radical prostatectomy.

In order to examine the characteristics of patients with nonpalpable prostate cancer (T1c cancer) in Japan, patients treated with radical prostatectomy were compared with those with palpable (T2) cancer. Prostate-specific antigen (PSA) level in patients with T2b disease was significantly higher than those with T1c and T2a tumors. At the time of radical prostatectomy, 78%, 71% and 31% of patients with T1c, T2a, and T2b, respectively, had organ-confined disease. When insignificant cancer was defined as volume 0.5 ml or less and Gleason score less than 5, only 2 of 34 (5.9%) with clinical T1c disease were clinically insignificant. T1c cancers were clinically significant and clinicopathological features of Tlc tumors were similar to T2a tumors. PSA measurement could detect potentially curable prostate cancer.

Adenocarcinoma↗
PubMed2002

Dose-adjusted preemptive therapy for cytomegalovirus disease based on real-time polymerase chain reaction after allogeneic hematopoietic stem cell transplantation.

We have prospectively evaluated the efficacy of real-time PCR-guided preemptive therapy for CMV diseases in allogeneic hematopoietic stem cell transplant recipients with grades II-IV acute GVHD. The dose of ganciclovir was adjusted according to the viral load determined by real-time polymerase chain reaction (PCR). On detecting CMV reactivation in the plasma, ganciclovir was initiated at a dose of 5 mg/kg body weight once daily, and the dose was increased to twice daily if viral load continued to increase after initiating ganciclovir. In 39 evaluable patients, CMV reactivation assessed by real-time PCR became positive in 30 (77%). One developed CMV gastroenteritis before PCR became positive. Thus the remaining 29 patients were treated preemptively with ganciclovir. The dose of ganciclovir was increased in 12 patients (41%) of preemptively treated patients for increasing viral load. CMV diseases were diagnosed in two patients (one gastroenteritis and one retinitis), and late CMV disease was diagnosed in one patient (gastritis). The treatment was generally well-tolerated, but three patients (10%) developed neutropenia (neutrophil count less than 1.0 x 10(9)/l). In conclusion, real-time PCR-guided preemptive therapy with decreased dose of ganciclovir is feasible and does not increase the frequency of CMV diseases if the dose is adjusted according to the viral load.

Adult↗
PubMed2002

Inhibition of proliferation of gastric epithelial cells by a cyclooxygenase 2 inhibitor, JTE522, is also mediated by a PGE2-independent pathway.

BACKGROUND: Cyclooxygenase-2 (COX-2) is one of the rate-limiting enzymes for prostaglandin synthesis from arachidonic acid. Although it is known that inhibition of cyclooxygenase activity delays ulcer healing, the regulatory relationship between COX-2 and its metabolites in gastric epithelial cell proliferation is not well known. AIM: To investigate whether COX-2 has an effect on gastric mucosal cell proliferation and further studied whether such effect is mediated only by prostaglandin E2 (PGE2), a representative metabolite of arachidonates in the gastric mucosa. METHODS: Artificial wounds of defined area size were created on complete monolayer cell sheets of isolated rat gastric epithelial cells and rat gastric cell line RGM1 under the addition of arachidonic acid or a COX-2 selective inhibitor, JTE522. Repair of wounds was assessed by monitoring wound size, with cell proliferation detected using 5-bromodeoxyuridine staining. Quantity of secreted PGE2 was measured by enzyme immunoassay. RESULTS: Stimulation of foetal calf serum increased the expression of COX-2 protein and inhibition of COX-2 retarded wound healing with reduction of cell proliferation. Arachidonic acid increased PGE2 production and accelerated restoration. Combination of JTE522 and arachidonic acid resulted in a marked retardation of wound healing compared to the control, but JTE522 did not completely suppress the increase in cellular PGE2 content following the addition of arachidonate. CONCLUSIONS: The difference in the effects of JTE522 on PGE2 production and on wound healing suggest that the involvement of COX-2 in gastric epithelial cell proliferation is not mediated solely by PGE2.

Animals↗
PubMed2002

Alteration of histological gastritis after cure of Helicobacter pylori infection.

BACKGROUND: It is still disputed whether gastric atrophy or intestinal metaplasia improves after the cure of Helicobacter pylori infection. AIM: To clarify the histological changes after the cure of H. pylori infection through a literature survey. METHODS: Fifty-one selected reports from 1066 relevant articles were reviewed. The extracted data were pooled according to histological parameters of gastritis based on the (updated) Sydney system. RESULTS: Activity improved more rapidly than inflammation. Eleven of 25 reports described significant improvement of atrophy. Atrophy was not improved in one of four studies with a large sample size (> 100 samples) and in two of five studies with a long follow-up period (> 12 months), suggesting that disagreement between the studies was not totally due to sample size or follow-up period. Methodological flaws, such as patient selection, and statistical analysis based on the assumption that atrophy improves continuously and generally in all patients might be responsible for the inconsistent results. Four of 28 studies described significant improvement of intestinal metaplasia [corrected]. CONCLUSIONS: Activity and inflammation were improved after the cure of H. pylori infection. Atrophy did not improve generally among all patients, but improved in certain patients. Improvement of intestinal metaplasia was difficult to analyse due to methodological problems including statistical power.

Gastric Mucosa↗
PubMed2002

Cisplatin-induced in vivo differentiation of human embryonal carcinoma.

OBJECTIVE: To investigate the differentiation of embryonal carcinoma (EC) by cisplatin, and the underlying mechanism, as untreated metastases of nonseminomatous germ cell tumours rarely consist of fully differentiated mature somatic tissues, but such mature metastases are more common after various treatments, including chemotherapy. MATERIALS AND METHODS: The TTSC-3 human testicular EC line heterotransplanted into nude mice was used as a target. After treating tumour-bearing mice with intraperitoneal injections of varying doses of cisplatin, the histopathology of the tumours was assessed and various gene expressions in the tumours determined by cDNA-array technology. RESULTS: When cisplatin at 1 mg/kg/week was injected intraperitoneally into TTSC-3-bearing mice, there was no effect on tumour growth. However, injecting cisplatin at 5 mg/kg/week induced a marked regression of the tumour. In contrast, cisplatin at 3 mg/kg/week had a modest inhibitory effect on tumour growth and induced tumour dormancy. Histological examination showed that 5 weeks after injecting cisplatin (3 mg/kg/week), primitive mesenchymal-like cells increased, and 10 weeks afterward cartilage and well-developed glands (teratoma) were apparent; at > 15 weeks afterward there were no EC cells visible. cDNA probes from reverse-transcribed mRNAs of TTSC-3 treated with cisplatin or saline for 10 weeks were compared to identify genes differentially expressed in cisplatin-treated TTSC-3. Of 1176 different human cDNA transcripts in cisplatin-treated TTSC-3, three genes (tumour necrosis factor receptor 1, caspase 8 and Apaf1), which are associated with apoptosis, were expressed markedly more than after saline injection. CONCLUSIONS: The intermediate dose of cisplatin inhibited tumour growth of EC by inducing differentiation and enhancing apoptosis-related gene expression. These findings suggest that cisplatin may play a significant role in the differentiation of EC in vivo.

Animals↗
PubMed2002

Recurrent acute myositis after allogeneic bone marrow transplantation for myelodysplasia.

A 54-year-old woman developed polymyositis 6 months after allogeneic bone marrow transplantation (BMT) for acute myelogenous leukemia transformed from myelodysplasia. At the onset of myositis, the patient had oral dryness, and the histology of oral mucosa was compatible with chronic graft-versus-host disease (GVHD). Muscle biopsy revealed focal muscle necrosis with massive lymphocytic infiltration. She was diagnosed with polymyositis, and the dose of cyclosporine was increased. Three months later, a complete resolution of myositis had been obtained, and the cyclosporine was tapered off. However, 51 months after the first episode of myositis, she again noted severe myalgia and was diagnosed with a recurrence of polymyositis based on high serum creatinine kinase (CK) and the findings of magnetic resonance imaging (MRI). At that time, chronic GVHD in other organs was not present. She achieved a second remission of polymyositis with cyclosporine, and has remained in remission for 4 years. The pathogenesis of myositis can be attributed to the immunologic imbalance characteristic of the post-allogeneic BMT setting.

Bone Marrow Transplantation↗
PubMed2002

Ex vivo expansion of human UC blood primitive hematopoietic progenitors and transplantable stem cells using human primary BM stromal cells and human AB serum.

BACKGROUND: In vitro maintenance and expansion of human hematopoietic stem cells is crucial for many clinical applications, and investigators have been using xenogeneic, especially murine, stromal cells for stem-cell expansion. In addition, many such culture systems utilize FCS-containing medium or serum-free medium that contains human- or animal-derived proteins. However, the possible transmission of infectious diseases has led to a debate about the safety of the delivery of grafts expanded in culture using cells and proteins of allogeneic or xenogeneic origin. Using primary human BM stromal cells, we have established an AB serum-based co-culture system to expand human primitive progenitors and transplantable stem cells. METHODS: Cord blood CD34+ cells were cultured on a monolayer of human BM-derived primary stromal cells with thrombopoietin (TPO), stem-cell factor (SCF) and flt3/flk2 ligand (FL) in the presence of either FCS or AB serum. One to three weeks later, cells were examined for total cells, CD34+ cells, CD34+ CD38- cells, and clonogenic progenitors. SCID mouse reconstituting cell (SRC) activity was also studied. RESULTS: Three weeks of culture with TPO, SCF, and FL supported more than a 250-fold expansion of CD34+ cells, CD34+ CD38- cells and CFU-C, regardless of the kind of serum used. SRC assay revealed that transplantable stem cells were moderately expanded as well. DISCUSSION: This ex vivo expansion system should prove valuable in clinical settings in which stromal cells and serum are available from recipients or stem-cell donors.

ADP-ribosyl Cyclase↗
PubMed2002

Comparison between high-resolution helical CT and pathology in breast examination.

PURPOSE: To determine whether high-resolution helical CT can show the architectural features of breast carcinomas of non-limited extent (non-BCLE) and to establish the CT characteristic morphology of non-BCLE. MATERIAL AND METHODS: We prospectively studied high-resolution helical CT of 136 invasive breast carcinomas before breast-conserving surgery. Non-BCLE were defined as ductal carcinomas in situ and invasive carcinomas beyond 1 cm from the edge of the dominant mass. Non-BCLE were defined as positive if enhanced beyond 1 cm from the edge of the focal enhancement on CT. After surgical resection, specimens were sliced in serial sections at 5-mm intervals, and the gross morphology and histology were correlated with the appearance of the preoperative CT lesion images. RESULTS: Non-BCLE were present in 47 invasive carcinomas. The sensitivity and specificity of non-BCLE evaluation by high-resolution helical CT were 70% and 89%, respectively. The morphology of non-BCLE on CT agreed with histologic findings. The morphological pattern on CT significantly correlated with intraductal tumor density adjacent to invasive tumor. CONCLUSION: Comparison of high-resolution helical CT with histologic data suggests that demonstration of a non-BCLE morphology can make the CT breast carcinoma local staging more accurate.

Breast↗